Upstream pull requests for systemd on GitHub are now running full system integration tests. Click on "Show all checks" on e. g. https://github.com/systemd/systemd/pull/2662
, there is an "ubuntu-ci" test.
These check out the pure code of that PR (no Debian/Ubuntu patches), build .debs out of those, install them into the testbed (Ubuntu 16.04 ATM), and run the autopkgtests in "TEST_UPSTREAM=1" mode, which skips/adjusts some Debian specific tests.
This will hopefully avoid introducing regressions that we can detect automatically before
the damage is done and things land in master. Indeed these tests detected a fair number of regressions last year already, but it was always an exercise in bisecting and manual investigation after the fact. Like this it should be much cheaper.
So, say it with Mr. T and a bad pun! (The "ubuntu-ci" test has my logo due to how GitHub works)